Today in Genes, Genomes, Genetics, UMBC postdoctoral fellow Sarah Stellwagen and co-author Rebecca Renberg at the Army Research Lab published the first-ever complete sequences of two genes that allow spiders to produce glue—a sticky, modified version of spider silk that keeps a spider’s prey stuck in its web.

The innovative method they employed could pave the way for others to sequence more silk and glue genes, which are challenging to sequence because of their length and repetitive structure. Better understanding of these genes could move scientists closer to the next big advance in biomaterials.

Sticky solutions

Spider silk is what spider webs are made of, and it’s been touted for years as the next big thing in biomaterials because of its unusual tensile strength combined with its flexibility. There are more than 45,000 known species of spiders, each of which makes between one and seven types of silk. However, despite many partial sequences, less is known about the full genetic structure of spider silk: Only about 20 complete genes have been sequenced. “Twenty pales in comparison to what’s out there,” Stellwagen says.

Plus, spider silk has proven tough to produce in large amounts. Spiders convert liquid blobs of silk into solid, spindly fibers in a complex process inside their bodies. Scientists can make the liquid, but “we can’t replicate the process of going from liquid to solid on a large industrial scale,” Stellwagen says.

Spider glue, however, is a liquid both inside and outside the spider. While the glue “does have its own challenges,” Stellwagen says, that difference might make spider glue easier to produce in a lab than silk.

Stellwagen sees great potential for spider glue applications as organic pest control. After all, she says, “This stuff evolved to capture insect prey.”

For example, farmers could spray the glue along a barn wall to protect their livestock from insects that bite or cause disease, and then could rinse it off without worrying about polluting waterways with dangerous pesticides. They could use glue similarly to protect crops from pests. It could also be applied in areas where mosquito-borne illnesses are prevalent. “It could also just be fun to play with,” Stellwagen says.

A “behemoth of a gene”

Before Stellwagen and Renberg’s work, which was funded by the Army Research Lab, the longest silk gene sequenced was about 20,000 base pairs. When she started this project, Stellwagen was expecting to sequence the glue genes quickly and then move on, building on what she learned from the sequence. Instead, it took her and Renberg two years just to finalize the sequence.

“It ended up being this behemoth of a gene that’s more than twice as large as the previous largest silk gene,” Stellwagen says. It was a long, hard road to the day she found Renberg in the lab and said, “I think our gene is 42,000 bases long. I think we finished it.” And in the end, it was taking a risk on a cutting-edge technique that finally yielded the complete sequence.

Not only was the gene exceptionally long, but, like spider silk genes, it has many repetitions of the same sequence of bases—A, T, G, and C—in the middle. Modern sequencing techniques (called “next generation sequencing”) work by generating DNA sequences for all of an organism’s genes, but chopped up in little pieces. Then, like solving a puzzle, scientists must match up the overlapping ends of the short sections to determine the entire sequence.

However, if your gene is repetitive, you need a single sequence, or “read,” that extends from before the repetitious region to beyond the end to know how many repetitions there are. If your repetitious section is long, as it is in the glue genes Stellwagen and Renberg studied, the chance that you would get the read you need with next-generation methods is slim.

Fortunately, “third-generation” sequencing techniques are now available. Third-generation sequencing produces longer reads, but fewer of them. Only by repeating the experiment several times do you have a chance of getting the reads you need to determine the number of repetitions and finally define the gene’s entire sequence. “It’s challenging,” says Stellwagen. “You’re picking a needle from a haystack.”

But it worked. After two years of going to the computer and not seeing positive results, Stellwagen and Renberg finally got the reads they needed to define the entire gene’s sequence.

Stellwagen is already thinking ahead to what comes next. “Now that we have a protocol for discovering full-length silk genes, what do silks from other species look like?” she asks.

“I’m super excited that I was able to finally figure out the puzzle, because it was just so hard,” Stellwagen says. While it was a much bigger challenge than she expected, “Ultimately we learned a lot, and I am happy to put that out there for the next person who is trying to solve some ridiculous gene.”

Banner image: Sarah Stellwagen (left) and her postdoctoral advisor Mercedes Burns work together in the lab. All photos by Marlayna Demond ’11 for UMBC.

Read the complete article in G3: Genes, Genomes, Genetics.

Learn how to use R, a free software program for statistical computing and graphics!

The Center for Social Science Scholarship is partnering with SAGE Campus to offer a free 30 day Introduction to R for Social Scientists online course.

The course will open on June 17.  It takes around 12 hours to complete, and learners will be given 30-day access to complete the course at their own pace.  Course objectives and more information are available here.

Enrollment is limited to 5 learners, on a first-come, first-served basis. Email socialscience@umbc.eduto indicate your interest, and please provide your full name, preferred email address, affiliation, and home department. 

Since enrollment is limited, please sign up only if you are certain you can complete the course!  We will confirm if you have been selected. If capacity is full, we will add your name to a waiting list as we gauge interest in offering this or similar courses again in the future. 

A new policy for proposal submission is being implemented by UMBC’s Office of Sponsored Programs (OSP).

As of August 1, 2019, OSP will require that proposals be received, in a ready-to-submit state, 3 days in advance of the proposal submission deadline. 

In addition, on each day at 8am, OSP will review all proposals that are due that day.  If a proposal is not in a ready-to-submit state by 8am on the day it is due, OSP will not send it forward.

Please make note that there is no grace period, and no exceptions will be made.  

The Maryland Institute for Policy, Analysis, and Research (MIPAR) supports UMBC social science faculty and graduate students by providing researchers with pre-award and post-grant management assistance. 

In order to meet the requirements of this new policy, MIPAR must have a PI’s fully completed proposal no later than five days prior to the submission deadline. This includes any documents needed for subawards. More time may be required if the proposal is large or complex.  

Please contact MIPAR as soon as you begin to consider preparing a proposal, so that MIPAR staff can help you establish and meet a feasible timeline.   

If you have any questions or concerns, please feel free to contact MIPAR:

Deb Geare, Associate Director

geare@umbc.edu

410-455-1081

Carolyn Flowers, Business Manager

cflowers@umbc.edu

410-455-1084

A new policy for proposal submission is being implemented by UMBC’s Office of Sponsored Programs (OSP).

As of August 1, 2019, OSP will require that proposals be received, in a ready-to-submit state, 3 days in advance of the proposal submission deadline. 

In addition, on each day at 8am, OSP will review all proposals that are due that day.  If a proposal is not in a ready-to-submit state by 8am on the day it is due, OSP will not send it forward.

Please make note that there is no grace period, and no exceptions will be made.  

The Maryland Institute for Policy, Analysis, and Research (MIPAR) supports UMBC social science faculty and graduate students by providing researchers with pre-award and post-grant management assistance. 

In order to meet the requirements of this new policy, MIPAR must have a PI’s fully completed proposal no later than five days prior to the submission deadline. This includes any documents needed for subawards. More time may be required if the proposal is large or complex.  

Please contact MIPAR as soon as you begin to consider preparing a proposal, so that MIPAR staff can help you establish and meet a feasible timeline.   

If you have any questions or concerns, please feel free to contact MIPAR:

Deb Geare, Associate Director

geare@umbc.edu

410-455-1081

Carolyn Flowers, Business Manager

cflowers@umbc.edu

It is no secret that children learn by watching the world around them. They pick up on everything and soak in all of the information they have gathered from watching their prominent adult figures. “Queens Girl in the World,” written by Caleen Sinnette Jennings and directed by Paige Hernandez, is a play told through the voice of a child. The child speaks about the influences of those around her that are evidently impactful and, if not, sometimes comical when she displays them.

Performed at Everyman Theater in Baltimore, Maryland, this socially relevant play is extremely important for everyone to see. This one-woman show was incredible, paying particular attention to the childlike eyes Jacqueline Marie Butler used to view the world. The audience was taken back to the days of their childhoods when they did not quite understand everything for what it truly was yet. A millennial might even compare the voice of Jacqueline to that of Junie B. Jones due to her childish inflection and sheltered sense of rebellion.

Dawn Ursula dominated this one-woman role down to its very core; not only acting as Jacqueline but also as her mother, father, friends and neighbors. Ursula engulfed the world and displayed it to the audience through the fresh, bright eyes of a young dark skinned child. Each character she played even had their own different way of walking, speaking and holding themselves.

Though Jacqueline led the protected and overly sheltered life of a middle class girl from a family living in Queens, her life in the late 1950s was far from perfect. She, giving some historical context, proudly mentioned that her father was the first black man to buy a house on their row, showing the audience that even though she might not know exactly why this was fantastic, Jacqueline was aware of some animosity surrounding this fact. She struggled to fit in with her neighbor Persephone, a lingo loving girl that called her “Jack,” and later with a schoolmate from her progressive school, where she was one of the only four black students.

Though entertaining and spectacularly well done, this performance subtly shifts from the innocent thoughts and experiences Jacqueline lived to more serious topics, like the racial divide in the 1950s. Beginning with the death of Malcom X, “Queens Girl in the World” displayed Jacqueline in the situation of knowing that this made her father sad while also showing a change in the stasis of the world she had built around herself.

Just as every young girl must go through changes, so must Jackie as she not only experiences physical changes, but also emotional and social ones. As the play progressed, the audience witnessed the growing up of a girl they had all come to feel attached to and invested in. More than anything, this upheaving performance showed the growth of a sweet girl exposed to the evils of the world far faster than she should have.

Tickets for future performances can be purchased at http://everymantheatre.org/queens-girl-repertory.

Dawn Ursula performing as Jacqueline Marie Butler. Photo by Teresa Castracane Photography.

This article has been updated.